Manufacture of imidazolines



Patented Sept. 24, 1940 PATENT OFFICE aziascz MANUFACTURE OFIMIDAZOLINES Edmund Waldmann, Klolterneuburg, and August Clrwala,Vienna, Germany, assignors, by mesne assignments, to General Aniline aFilm Corporation, New York, N. ware Y., a corporation of Dela- NoDrawing. Application March 22, 1939, Serial No. scam. in Austria April4, 1m

This application is a continuation-in-part of application Serial No.94,120, filed August 3, 1936. This invention relates to the manufactureof imidazollnes containing aliphatic radicals of high molecular weightas substituents at the 2- carbon atom by heating with a fatty acid or acarboxylic acid of high molecular weight to high temperatures,preferably to temperatures lying between 200 and 300 C., a mixtureconsisting on 1 the one hand of a base having a primary aminogroup and asecond primary or secondary aminogroup, which are in 1:2 position toeach other, the

two carbon atoms in 1+2-posltion being linked by a single bond, and on.the other hand a salt of such base formed from a strong acid.

Suitable bases having a primary amino-group and a second primary orsecondary amino-group in 1:2 position to each other areethylenediamine'; products such as diethylenetriamine,triethylenetetramine, tetraethylenepentamine; homologues ofethylenediamine such as 1:2-propylenediamine, 2:3-butylenediamine,N-methylethylenediamine.

Suitable strong acids for forming the salts are in particular mineralacids, such as hydrochloric acid, hydrobromic acid, sulfuric acid, andthe like.

Suitable fatty acids of high molecular weight are in general aliphaticacids containing more than 8 carbon atoms, for instance caprylic acid,lauric acid, stearic acid, palmitic acid, oleic acid, also mixtures ofthese acids obtainable by saponifying natural fats like olive oil,tallow, palm oil; also cycloaliphatic acids such as naph- 5 thenic acidsand the like.

Instead of the fatty acids there may be used suitable derivativesthereof such as esters, amides, anhydrides or halides; according to theselection of the derivative to be used, the simultaneous use of the freebase or the salt of the base may, if desired, be omitted, for in thecase of halides the suitable mixtures leading to the desired result areformed, due to the mineral acid becoming free, in the course of theacylation.

Quite generally, the new process consists .in heating with a productselected from the group consisting of fatty acids of high molecularweight 50 and the salts, amides, halides and esters there-;-

of, a mixture consisting on the one hand of a base which issubstituted-at two carbon atoms adjacent to each other by an amino-groupeach, of which amino-groups one contains two hydrogen atoms and theother at least one hydrogen atom, and on the ther hand of a salt of suchbase with a strong acid, the heating being carried out at a hightemperature.

The procedure may also be such that first of all the salt of themono-acyl compound is prepared. The process then consists in heating toa high temperature a salt formed from a strong acid and such a diaminemonoacylated with a fatty acid of high molecular weight, in which thetwo amino groups are bound to two carbon atoms adjacent to each other,one of which amino groups containing two hydrogen atoms and the other atleast one hydrogen atom.

. In the preferred mode of operating, the mixture made in accordancewith the invention is heated to a temperature of 250-290 C. If, forexample,there is used a quantity of lauric acid, ethylenediamine andethylenediamine-hydrochloride the hydrochloride which forms a sedimentdissolves very quickly in this interval of temperature, even with onlygentle stirring, and at the same time causes formation of theundecyl-imidazolinehydrochloride. This reaction may also be conducted ata temperature lower than 250 C. by heating for a longer period. The useof a vacuum during the second half of the condensation is useful.

When the condensation to the imidazoline derivative starts from amixture of fatty acid amine and aminehydrochloride, the three componentsof the mixture are advantageously selected so that for 1 mole of thefatty acid or its derivative there are at least 1 mole of the diamineand the salt-like bound mineral acid. In using 1 mole of lauric acidtherefore, there should be mole ethylenediamine and /2 moleethylenediaminehydrochloride, corresponding with the equation CnHaCaminehydrochloride at about 250-290 C. there is obtalned'the reaction inthe sense of the following equation:

Cu I ONHOs cNHOOOnHI'I-N Q WQI the product being againundecylimidazoline- 1o hydrochloride in approximately quantitativeyield. If, however, the parent material is themonolauroylethylenediaminehydrochloride which already contains in itselfper 1 mole fatty acid 1 mole of ethylenediamine and 1 mole ofhydrochloric acid, it sumces to heat this hydrochloride by itself toabout 250-300 C. in order to obtain an excellent yield'of thehydrochloride of undecylimidazoline. This reaction can also be carriedout with the other mono-acyl-derivatives which are obtained from thediamines and the fatty acids of high molecular weight mentioned inparagraphs 2 and 4 of this specification.

Under the effect of the amine salt, particularly the hydrochloride, onefinds at comparatively high temperature of reaction evidently anelimination of the acid amide at first formed (as may be seenparticularly clearly from the example of dilauroylethylenediamine) andthen a combination of the eliminated material directly to theimidazoline hydrochloride. Philipps (Journal of the Chemical Society ofLondon, 1928, page 2393 and following; Chemisches Zentralblatt 1928,vol. 2, page 2466) is of opinion that the formation of benzimidazoles orimldazolines from the acyl-derivatives of the corresponding diamines byboiling with hydrochloric acid occurs of itself in such a manner thatthe acid amide is first saponified and the eliminated portion uniteddirectly to the benzimidazol or imidazoline. These imidazolines of highmolecular weight in the form of their salts are freely soluble in water;solutions foam and have good capillary active properties. They may beused with advantage for improving dyeings on vegetable fibers.

Sulfo-groups may be introduced in their molecules by the methods whichhave become known from French Specification No. 796,917. Theseimidazoline-sulfonates of high molecular weight 5 are also valuable aswetting, foaming, washing, emulsifying and dispersing agents. They arevaluable as assistants in the textile industry.

The following examples illustrate the invention, the parts being byweight:

Example 1 Into a stirring vessel provided with a thermometer and aninverted condenser there are charged 284 parts of stearic acid, 93 partsof ethylenediaminehydrochloride, 56 parts of ethylenediaminehydrate. Themixture is heated while stirring to 120 C. and the temperature is raised'within 90 minutes to 185 C., whereby between 170 and 185 C. a smallproportion of a clear liquid distils (ethylenediaminehydrate and water).The mixture is now heated within 30 minutes to 230 C. and then within 15minutesto 290 C. The mass is kept for a short time at this temperature,which may be raised to 300 C. until a sample of the mass, tested withwater, shows that it is soluble in water to a clear solution; theheating is then interrupted and the mass cooled. The brownish mass,which is crystalline when cold, consists almost exclusively ofheptadecyl- .7 imidazolinehydrochloride.

Afreebasemaybeseparatedinknownmanner by dissolving the hydrochloridewith water and liberating the base with an alkali-hydroxide which canthen be directly filtered. or extracted by means-of benzene. Forfurther. purification 6 the product may be crystallized from a mixtureof 3 parts of methyl alcohol and 1 part of water. whereby2-heptadecylimidazoline is obtained in crystalline scales melting at94-95" C.

' Example 2 In an apparatus such as is described in Example 1 there isheated a mixture of parts of lauric acid, 40 parts ofethylenediaminehydrate, 60 parts of ethylenediaminehydrochloride in 15manner described in the same example. As soon as a sample of the mass isclearly soluble in water, the heating is interrupted. On cooling, themass solidifies in crystalline form; it consists of 2-undecyllmidazolinehydrochloride. The base 2 liberated in the usualmanner from this salt may be purified by recrystallization from alcoholof 50 per cent. strength, whereby it is obtained in the form ofcolorless laminae which melt at 82 C.

Example 3 26 In an apparatus such as is described in Example 1 there isheated to 180 C. a mixture of parts of oleic acid, 15 parts ofethylenediaminehydrate; the mass which at first is somewhat 30 foamyboils finally gently as soon as the water has been distilled. Aftercooling to 120 0. there are added another 15 parts ofethylenediaminehydrate and heating is renewed to C. 37.5 parts ofethylenediaminehydrochloride are now 35 added, whereupon the temperatureof the mass is raised to 280 C. within 15 minutes and kept there for 10minutes. The mass is then allowed to cool to 120 C., another 10 parts'ofethylenediaminehydrate are added, and the mixture is 40 heated within 20minutes to about 300 C. and kept at this temperature until a sampledissolves clearly in water, whereupon the heating is immediatelyinterrupted.

In this manner there is obtained the 2-hepta- 5decenylimidazolinehydrochloride in the form ofv a semi-solid brownishmass which dissolves clearly in water with the formation of a stronglyfoaming solution from which the base may be isolated in the usualmanner. 50

Example 4 I Ezram le 5 8.5 parts of N-N-Di-lauroylethylenediamide areheated with 3.3 parts of ethylenediaminehydrochloride in an open flask,while stirring, in such a manner that after 5-10 minutes the mixture hasa temperature of about 270-280 C. The 70 heating is continued foranother 10 minutes to 280-290 C., whereby the greater quantity of thehydrochloride passes into solution. A sample then dissolves clearly inwater.

Caustic soda solution precipitates from the' aqueous solution theundecylimidazoline which is the product of reaction in approximatelyquan-. titative yield.

Example 6 55 parts of stearic anhydride, 9.5 parts of ethyl-;nediaminehydrate and 14.4 parts of ethylenediamlnehydrochloride arecondensed in the usual manner as described in Example 1' so as to formthe heptadecylimidazolinehydrochloride. A whitish-yellow melt isobtained which forms with water a clear, strongly foaming dispersion.

Ezamle 8 A mixture of 9 grams of ethylenediaminehydrate and 44 grams ofmyristic anhydride is gradually heated, while stirring, to 110 C. to 130C. 8 grams of ethyienediaminedlhydrochloride are added to the clear meltand the reaction mass is further heated to 280 C. to 290 C. until;

the melt dissolves clearly in water.

The tridecane A2 imidazolinehydrochloride thus obtained is a light brownmass which readily dissolves in water with formation of foam and mayreadily be transformed into the base by means of alkalies.

We claim:

1. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid anhydrides and naphthenic acid anhydrideswith half a mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogen atoms and theother at least one hydrogen atom, and with half a mol of a salt of sucha base with a strong acid, the reaction being carried out at a hightemperature.

2. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid anhydrides and naphthenic acid anhydrideswith half 8. mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogen atoms and theother at least one hydrogen atom, and with half a mol of a salt of sucha base with a strong acid, the reaction being carried out at a hightemperature while using an excess of the free base.

3. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid anhydrides and naphthenic acid anhydrideswith half a mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogen atoms and theother at least one hydrogen atom, and with half a mol of a salt of sucha base with a strong acid, the reaction being carried out at a hightemperature while using an excess of the salt of the base with a strongacid.

4. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid anhydrides and naphthenic acid anhydrideswith half a mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogen atoms and theother at least one hydrogen atom, and with half a mol of a salt of sucha base with a strong acid, the reaction being carried out at a hightemperature while using an excess of the free base and the salt of thebase with a strong acid.

5. Process for the manufacture of 2-substltuted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the fatty acid anhydrides and naphthenic acid anhydrideswith half a mol of a base which is substituted at two carbon atomsadjacent to each other and linked by a single bond by an amino groupeach, of which amino groups one contains two hydrogenatoms and the otherat least one hydrogen atom, and with half a. mol of a salt of such abase with a strong acid, the reaction being carried out at temperatureslying between 200 C. and 300 C.

6. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the anhydrides of the fatty acids containing 10 to 18carbon atoms with half a mol of a base which is substituted at twocarbon atoms adjacent to each other and linkedgby a single bond by anamino group each, of which amino groups one contains two hydrogen atomsand the other at,

least one hydrogen atom, and with half a mol of a salt of such a basewith a strong acid, the reaction being otherwise carried out at a hightemperature. I

7. Process for the manufacture of 2-substituted imidaaolines whichcomprises reacting one mol of a product selected from the groupconsisting of the anhydrides of the fatty acids containing 10 to 18carbon atoms with half 9. molof ethylene diamine and half a mol of asalt of ethylene diamine with a strong acid, the reaction being carriedout at temperatures lying between 200 C. and 300 C.

8. Process for the manufacture of 2-substituted imidazolines whichcomprises reacting one mol of a product selected from the groupconsisting of the anhydrides of the fatty acids containing 10 to 18carbon atoms with half a tool of ethylene nnmmn wannmmz. .wcus'r CHWALA.

